Vitamin D: It's not just about Osteoporosis and Bone Health
There are numerous reasons why I chose the title, The Whole-Body Approach to Osteoporosis, for my book. Not only should we look at the whole body when searching for causes of bone loss, but the fact that there are so many pieces of the "bone puzzle" that fit into other parts of the body, we really can't separate skeletal physiology from the other organs and tissues during the diagnostic process.
Take vitamin D for instance. We all know that vitamin D is important for bones because it helps us absorb more calcium from the gut. But did you know that vitamin D is also important for the immune system to effectively ward off disease?
Vitamin D, or 25 hydroxyvitamin D [25(OH)D] is actually a precursor hormone. In this form, vitamin D doesn't actually do us much good. It needs to be converted in the liver and kidneys into the active form of vitamin D called 1,25 dihydroxyvitamin D [1,25(OH)2D3] or calcitriol.
By the time 25(OH)D is converted into 1,25(OH)2D3 it is a true steroid hormone that targets many genes.
You can think of 1,25(OH)2D3 as being similar to what a can opener is to a can, or what a spark plug is to an engine.
This active form of vitamin D turns on up to 1,250 genes in the body. That is a huge percentage of the number of genes we carry, and therefore, vitamin D greatly impacts who we are.
In a recent "Letter to the Editor"(1) in the Journal of Bone and Mineral Research, Assistant Professor Dr Toshihiro Sugiyama from the Department of Orthopedic Surgery, Saitama Medical University, Japan, called upon researchers to find consensus in determining the "adequate level" of vitamin D for bone health.
In fact, most medical doctors and researchers believe that the effects of vitamin D on bone mineral density scores should be the determining factor in setting supplemental dosing recommendations.
But this approach fails to recognize the full impact that vitamin D has on the body.
Currently, blood levels of vitamin D [25(OH)D] below 20 ng/ml are considered deficient. Most doctors feel that 30 ng/ml is adequate for maintaining good bone health. In order to maintain 30 ng/ml the average person needs to consume 400 to 800 International Units (IU) of vitamin D/day.
Indeed, much of the latest research, as sited by Dr Sugiyama, does indicate that 800 IU of supplemental vitamin D may be good enough. But does good enough or adequate cut it when we have fragile, osteoporotic bones and a high risk for fracture?
In addition, as I have eluded to earlier, there is more to the vitamin D story than just bones. With vitamin D affecting the genetic expression of over a thousand genes and sparking countless biological pathways, maybe adequate isn't good enough. Maybe we need to shoot for optimal intakes.
Vitamin D, as it turns out, is important not just for skeletal health but deficiency has been linked to infectious diseases such as tuberculosis; cancers such as leukemia and colorectal, ovarian, and breast cancer; autoimmune disorders such as multiple sclerosis and type 1 diabetes; cardiovascular disease, and others.
Vitamin D impacts just about every nook and cranny in the body. It affects everything from cell birth, cell growth, and cell death to the production of microbial peptides in white blood cells, to enzymes in our kidneys that help keep our blood pressure normal, and to insulin for blood glucose regulation.
Vitamin D is also involved in the production of osteocalcin, the protein released by osteoblasts for the nucleation of the hydroxyapatite crystal during new bone formation. Yes, I want more than just adequate vitamin D, I want optimal levels in my blood.
In a study(2) that investigated the effects of vitamin D supplementation on genetic expression in humans, Dr. Arash Hossein-nezhad, et al. looked at the difference in genetic effects when dosing with either 400 or 2,000 IU vitamin D/day. What Dr. Hossein-nezhad, a Research Assistant Professor of Endocrinology, Diabetes & Nutrition at Boston University, found was startling.
Dr. Hossein-nezhad's research found "at least a 1.5 fold alteration" in the expression of genes when individuals supplemented with vitamin D. Further, by increasing D supplemental intake from 400 IU to 2,000 IU/day there was a "continuum in gene expression in response to increasing serum 25(OH)D levels."
"Any improvement in vitamin D status will improve expression of genes that have a wide variety of biologic functions." The researchers concluded that "to maximize vitamin D's effect on gene expression may require even higher doses than 2,000 IU of vitamin D3 daily."
In my office, I like my patients' vitamin D blood levels to be at least 40 ng/ml in the winter.
Now is the time to ask your doctor to order a vitamin D test, especially if you live in a northern climate where the sun's rays are weak during the winter months.
By testing vitamin D levels in the winter, and adjusting your intake accordingly, you can be assured of optimal blood levels year round. Due to the added benefit of sun exposure during the summer months, levels may rise to 50 or even 60 ng/ml. There appears to be no added health benefit to going higher than this.
What I have found is that the 2,000 IU of vitamin D that people receive from taking 3 OsteoSustain tablets (providing 1,000 IU of D) and 3 OsteoStim (providing 1,000 IU) each day is typically enough to not only keep bones healthy but also keep vitamin D levels optimal throughout the year.
That said, testing is very important as some individuals require additional vitamin D supplementation to maintain at least 40 ng/ml throughout the year.
The Whole Body Approach to Osteoporosis.
From my bones to yours,
Irma Jennings, INHC, Holistic Bone Coach
1) Sugiyama, T. 2019. Letter to the Editor: Towards a Consensus over Vitamin D Supplementation and Bone Health. JBMR. February 7, https://doi.org/10.1002/jbmr/3634.
2) Hossein-nezhad, A, et al. 2013. Influence of Vitamin D Status and Vitamin D3 Supplementation on Genome Wide Expression of White Blood Cells: A Randomized Double-Blind Clinical Trial.PLOSONE. 8(3)258725.